The Beach/Caribe is their basic, entry-level complex and the food quality & variety is definately different when compared to the moderate level Colonial/Tropical and/or the deluxe level Palace!
While the Beach/Caribe has a pristine beachfront, as was said, snorkeling is best off the Palace beachfront and also off the sports pier.
The cost to upgrade to the air conditioned buffets at the Colonial/Tropical is $5US per person per meal. The cost to upgrade to one of their four a la cartes is $15US per person per dinner, subject to availability.
FYI - the Barcelo is not known for its' organized teen activity programs! The best program in the region for them can be found at the Grand Palladium complex, just to the south.